Most Taliban bombs are just ammonium nitrate fertilizer (tags)
According to this Washington Post article most of the bombs the Taliban use against the Americans are simple bombs made out of nothing more then ammonium nitrate fertilizer which is set off with a blasting cap made out of a acid filled pen or glass tube.
Habeas Ends, Time to Arm (tags)
Here are a couple of things almost anyone can easily acquire, which can quickly be used to make significant weapons: Nitrate Fertilizer (gardening supplies), powdered Aluminum (paint store), and sparklers. Just get this stuff, now, not later. Vanadium Pentoxide (chem supplier?) and battery acid (automotive) are also pretty handy.